A Saturn S-II stage as a first stage with an S-IVB second stage, with four UA-1207 solid rocket boosters.
Artwork of a three-stage rocket designed by Krafft Ehricke around 1953. 126 feet tall, it would be capable of orbiting 11,000 pounds of payload into a 600 mile circular orbit. Liftoff weight would be 1.3 million pounds.
The first stage, here being shown dropped, would be parachute recovered. the second stage would be expended; the third stage would be used to built up a space station. If you can’t immediately tell where stage 2 ends and stage 3 begins, it’s because stage 3 is the central cylinder, with stage 2 being wrapped around it. This sort of staging arrangement was considered fairly often in the days before they actually had to build these things.
It would be able to land 3,000 pounds on the moon or shoot 5,000 pound probes past Mars or Venus.
In 1968, Boeing (manufacturer of the S-IC stage of the Saturn V) put out an illustration of advanced derivatives of the Saturn V. Published in the XIXth International Astronautical Congress, these included the Saturn V-25(S)U, which was a stretched Saturn V with improved F-1 and J-2 engines, with four 156″ diameter solid rocket boosters; the Saturn V/4-260, which used the same improved Saturn V, but with four 260″ diameter solid rocket boosters, with additional first stage liquid propellant in tankage ahead of the solid boosters. Additionally, the payload shroud could be increased in diameter from ten meters to 78 feet,and up to 290 feet in length. Further included was the Saturn V-XU, which was four improved Saturn V’s clustered together (both first and second stages), with a payload shroud 86.5 feet in diameter and 240 feet long; and an all-new Post-Saturn concept with a 75-foot-diameter core vehicle with optional 260″ diameter solid rocket boosters (up to twelve) and a payload shroud up to 120 feet in diameter. A payload of up to 4.2 million pounds was envisioned.
Two length options were shown… 410 feet and 500 feet. The 410 foot-long vehicles could be assembled within the VAB; the 500 foot-long vehicles would require that the payload be stacked onto the vehicle outside the VAB using a new crane mounted to the VAB roof.